In the earth drilling art, it is well known to use downhole motors to rotate drill bits on the end of a non-rotating drill string. With the increasingly common use of directional drilling, where the well is drilled in an arc to produce a deliberately deviated well, bent subs have been developed for guiding the downhole motors in a desired drilling direction. The bent subs are angled, and thus cannot be used in association with rotating drill strings.
This invention is directed towards a tool that permits steered directional drilling with a rotary drilling tool.